I have two iMacs and just installed OS X Lion (clean install) on one of them (let's call it iMac A). I did a Time Machine backup and restored that backup to my other iMac (B) to avoid installing twice. Everything works perfectly except that Google Chrome is extremely slow on iMac B (where the Time Machine backup was restored to). Opening a new tab is slow, opening a web page is slow etc. Safari on B is fast and works as it does on A, so it's just on B that Chrome is slow (and Chrome is my preferred browser, so I'd like to get it up to speed).

To solve the problem on B, I've tried uninstalling Chrome (see How do I uninstall Google Chrome *completely* from my Mac?) but uninstalling and reinstalling did not do the trick.

Does anyone have an idea why it is slow only on B and how to fix it?

2 Answers 2


Weird issue indeed. Have you tried to use Chromium to see if the issue is the same? I'm interested to see if the slowness persists using a slightly different flavor of the browser. If the slowness still persists, we know its likely a problem with the shared resources/files the browsers use.

Let me know

  • Haven't tried Chromium so I'll give it a try. Do you know of a download link (already built as building is not in my skill set) that works? (can't find one that works on chromium.org)
    – rassom
    Aug 2, 2011 at 19:06
  • Sure. Go here, scroll the end of the page, find the highest build number and download the chromium mac, zip file. unzip and drag the app into your applications folder. These are nightly builds so they might now be all that stable but for the purpose of our troubleshooting it should be ok. Aug 2, 2011 at 19:28
  • Done. Unfortunately it didn't make a difference. Chromium is also very slow. Any ideas as to what the problem could be/how to fix it?
    – rassom
    Aug 2, 2011 at 20:25
  • hmmm...really weird. graspiong at straws here but maybe try enabling hardware acceleration? Aug 2, 2011 at 21:30
  • Unfortunately that did not solve the slowness either. Sidenote: I've found out that it is slowest in the beginning of a web page request - once it begins loading a page things go quicker (although not as fast as on the other iMac (A) which is an older model, so this one (B) should be faster). Any other ideas to try? Otherwise I'll go ahead and do a fresh OS X Lion install on B to solve the problem.
    – rassom
    Aug 3, 2011 at 15:55

I've now installed first OS X Lion from scratch, then installed Google Chrome - and Chrome performance is good again. Weird that it requires a complete OS re-install to fix the performance of Chrome!

UPDATE 22 September. I have now received the solution below from Parallels support and have confirmed that it works (i.e. restores performance of Google Chrome):

  1. Please go to /Library/Preferences/Parallels
  2. Locate network.desktop.xml file. Make a backup copy of it to Desktop.
  3. Open the file and locate the following string:

    <ParallelsNetworkConfig schemaVersion="1.0" dyn_lists="VirtualNetworks 1 VZNetworkConfig 0">
    <VirtualNetworks id="0" dyn_lists="VirtualNetwork 12">
  4. Change the value in IPv6Enabled to 0 (1 => 0)

  5. Save changes and close the file.

  6. Quit Parallels Desktop if it is running.
  7. Open Terminal and issue these commands:

    sudo launchctl stop com.parallels.desktop.launchdaemon

wait for 10 seconds, then this commmand (still in terminal):

sudo launchctl start com.parallels.desktop.launchdaemon
  1. Start Parallels Desktop, go to the Virtual machine Configuration - Hardware and change the Network Mode to 'Bridged'
  2. Check if the issue persists.
  • I found the real culprit that causes Google Chrome to get very slow on machine B but hadn't thought it as a possibility: Parallels Desktop (v6.0.12094). I did install Parallels Desktop on B after my time machine restore, so it turns out the problems had nothing to do with time machine (restore). After installing Lion on B from scratch, Chrome speed was good until I last night installed Parallels Desktop and suddenly my Chrome was slow again. Reverted to a time machine backup just before the Parallels Desktop installation and speed is good again. I will raise this issue the Parallels company.
    – rassom
    Aug 7, 2011 at 11:20
  • PS. Once PD has been installed, the harm is done. Even uninstalling Parallels Desktop (move PD to trash/emptry trash) doesn't help on the Chrome being slow. A time machine restore to before PD installation or a fresh Lion installation is only way to get Chrome up to speed again.
    – rassom
    Aug 7, 2011 at 11:30

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .